SBC Cam timing problem... 12 deg retarded...

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MadBill
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Re: SBC Cam timing problem... 12 deg retarded...

Post by MadBill »

It is very difficult to precisely measure the max lift point. With symmetrical lobes, the usual process is to check the angles that give say the 0.050" less than max lift on the opening and closing flanks and split the difference. This would likely get your measured ICL angle closer to spec with the 0.162" rise @ TDC.

That said, you are plenty close enough to the supplied spec now; it's time to carry on with the build and then hit the road! Every engine is unique in some way so if time and money permit, adjusting the cam in 2-3°increments of advance and retard might yield measurable gains.
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Re: SBC Cam timing problem... 12 deg retarded...

Post by Bob Hollinshead »

You could also set the cam at the intake closing point you want and see where the other events fall.
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CREngines
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Re: SBC Cam timing problem... 12 deg retarded...

Post by CREngines »

i had this happen this spring on a custom. it was 11 or 12 degrees off. The masters were switched and the lobes were backwards. Check for that because it can happen real easy.
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Re: SBC Cam timing problem... 12 deg retarded...

Post by dat383 »

Thanks for the relies.The crank sprocket is aligned correctly with the numbers on the tooth.I have also tried two different brands of timing sets,with the same results.
I have chosen to ignore the conventional marking points and timed it to the cam specs by advancing the cam 1 tooth and retarding the crank sprocket 6 deg.This puts both the ICL and lift@TDC where it needs to be.

I just gonna make sure i write this down and put it with my cam sheet for future reference....I need a beer......


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Re: SBC Cam timing problem... 12 deg retarded...

Post by JohnnyB »

I need a beer......

Beer fix's most everything........... :lol: :lol:
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BrazilianZ28Camaro
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Re: SBC Cam timing problem... 12 deg retarded...

Post by BrazilianZ28Camaro »

JohnnyB wrote:
Beer fix's most everything........... :lol: :lol:

Yeah, but drink a couple beers before the cam degree and you'll never see the timing dots aligned!


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Re: SBC Cam timing problem... 12 deg retarded...

Post by CREngines »

dat383 wrote:Thanks for the relies.The crank sprocket is aligned correctly with the numbers on the tooth.I have also tried two different brands of timing sets,with the same results.
I have chosen to ignore the conventional marking points and timed it to the cam specs by advancing the cam 1 tooth and retarding the crank sprocket 6 deg.This puts both the ICL and lift@TDC where it needs to be.

I just gonna make sure i write this down and put it with my cam sheet for future reference....I need a beer......


Cheers, Gary.
Make sure you have the opening and closing on both lobes before you put it together like that.
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